The Journal of Medical Microbiology, Vol 48, Issue 2 215-218, Copyright © 1999 by Society for General Microbiology
Minimal inhibitory effect of male urine on detection of Chlamydia trachomatis by Roche Amplicor PCR
E. L. Chan, K. Brandt, N. Antonishyn and G. B. Horsman
Department of Clinical Microbiology, Provincial Laboratory, Regina, Saskatchewan, Canada. echan@health.gov.sk.ca
A total of 1120 specimens of fresh urine from male patients was tested for
Chlamydia trachomatis with the Roche Amplicor PCR Kit and an in-house PCR
assay. The in-house PCR had an internal control to monitor inhibitory
effects of clinical specimens on the PCR assay. All urine samples were
processed within 24-48 h of collection and DNA was extracted on the same
day that the assays were performed. Specimens that gave discrepant PCR
results were tested by a reference laboratory with both the Roche Amplicor
kit and their in-house PCR assay. Of the 1120 samples, 174 gave positive
results in both assays and 942 gave negative results in both assays. Only
one specimen showed an inhibitory effect on the in-house PCR assays, as
indicated by failure to produce the internal control PCR product. This
specimen gave negative results by both assays. There were four discrepant
results in the two PCR assays. One was a false negative result obtained
with the Roche Amplicor kit and the remaining three discrepant results
could not be resolved because there was an insufficient quantity of
specimen. This study demonstrated that the Roche Amplicor kit could
effectively detect C. trachomatis in urine specimens from this population
of male patients with negligible inhibition of PCR.
